Electrophoretic display panel with selective character addressability

An electrophoretic display apparatus having a selectively erasable display including a plurality of character lines, said display apparatus being capable of allowing a user to erase at least one character in one of said character lines which has been written to said display without having to completely re-write every character in said character line, comprising:

• a fluid-tight envelope having a portion thereof which is at least partially transparent;
• an electrophoretic fluid contained within said envelope, said fluid having pigmented particles suspended therein, and a plurality of row and column electrodes passing through said envelope and said fluid;
• a plurality of anode segments passing through said envelope, wherein each character line of said display is defined by at least one of the anode segments and by a corresponding group of row and column electrode intersections;
• line control means operable in a partial erasure mode to apply a first potential bias of a given polarity between an anode segment corresponding to a selected character line and a corresponding group of row and column intersections, said first potential bias being applied for a first given duration of time sufficient to cause said pigment particles to move relative to said intersections and partially erase said selected character line, said line control means being further operable in a rewriting mode to apply a second potential bias of an opposite polarity between said anode segment and said group of row and column intersections for a second given duration of time sufficient to partially rewrite every character of said selected character line except for at least one character selected for erasure, and said line control means being further operable to sequentially apply said first and second potential biases until said at least one of said characters selected for erasure is no longer displayed.